Multiple α sub-variants and anisotropic mechanical properties of an additively-manufactured Ti-6Al-4V alloy
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2021年第11期
论文作者：Yinling Zhang Zhuo Chen Shoujiang Qu Aihan Feng Guangbao Mi Jun Shen Xu Huang Daolun Chen
文章页码：113 - 124
摘 要：Additive manu facturing（AM） is a promising material processing method which gains significant momentum in the aerospace and biomedical industries.However,the anisotropy in the mechanical properties of additively-manufactured materials is still poorly understood.This study was aimed at elucidating crystallographic feature-anisotropy-mechanical property relationship for a Ti-6Al-4V alloy manufactured via selective electron beam melting（SEBM）.Abundant α lamellae with six variants were present inside the columnar prior-β grains with a <100> fiber texture during β→α phase transformation.The six αvariants followed the Burgers orientation relationship of {110}β//{0001}α and <1-11>β//<11-20>α.Multiple sub-variants in each α variant were observed for the first time.The anisotropy in the mechanical properties was mainly related to the relative amount of six α variants.While the horizontally-oriented samples had a lower yield strength,they exhibited a higher ductility and longer fatigue life than the vertically-oriented samples.Cyclic softening occurred at higher strain amplitudes,and cyclic stabilization sustained at lower strain amplitudes.Fatigue crack mainly initiated from the specimen surface at lower strain amplitudes,while multiple crack initiation tended to occur at higher strain amplitudes.Crack propagation was characterized by fatigue striations along with some secondary cracks.
Yinling Zhang1,2，Zhuo Chen3，Shoujiang Qu1,4，Aihan Feng1,4，Guangbao Mi5，Jun Shen1,6，Xu Huang5，Daolun Chen2
1. School of Materials Science and Engineering,Tongji University2. Department of Mechanical and Industrial Engineering,Ryerson University3. Aerospace Hiwing (Harbin) Titanium Industrial Co.,Ltd.4. Shanghai Key Lab.of D&A for Metal-Functional Materials,School of Materials Science & Engineering,Tongji University5. Aviation Key Laboratory of Science and Technology on Advanced Titanium Alloys,AECC Beijing Institute of Aeronautical Materials6. College of Mechatronics and Control Engineering,Shenzhen University
摘 要：Additive manu facturing（AM） is a promising material processing method which gains significant momentum in the aerospace and biomedical industries.However,the anisotropy in the mechanical properties of additively-manufactured materials is still poorly understood.This study was aimed at elucidating crystallographic feature-anisotropy-mechanical property relationship for a Ti-6Al-4V alloy manufactured via selective electron beam melting（SEBM）.Abundant α lamellae with six variants were present inside the columnar prior-β grains with a <100> fiber texture during β→α phase transformation.The six αvariants followed the Burgers orientation relationship of {110}β//{0001}α and <1-11>β//<11-20>α.Multiple sub-variants in each α variant were observed for the first time.The anisotropy in the mechanical properties was mainly related to the relative amount of six α variants.While the horizontally-oriented samples had a lower yield strength,they exhibited a higher ductility and longer fatigue life than the vertically-oriented samples.Cyclic softening occurred at higher strain amplitudes,and cyclic stabilization sustained at lower strain amplitudes.Fatigue crack mainly initiated from the specimen surface at lower strain amplitudes,while multiple crack initiation tended to occur at higher strain amplitudes.Crack propagation was characterized by fatigue striations along with some secondary cracks.
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